Abstract: A test fixture includes a base and an adjustable structure. The adjustable structure includes a limiting block, a locking block, and a fixing member. The limiting block is disposed on the base. The locking block is disposed on the base and abuts an edge of the limiting block to lock the limiting block in position. The fixing member is disposed on the limiting block to fix the limiting block on the base. When the locking block is moved from a first position to a second position, the locking block unlocks the limiting block, the fixing member is loosened, and the limiting block can rotate on the base. After the limiting block is rotated, the locking block is moved from the second position to the first position to lock the limiting block, and the fixing member is tightened to fix the limiting block on the base.

Abstract: A method for determining local position of an optical element associated with an optical path for transporting a laser beam in a working head of a machine for laser processing a material, includes generating a measurement beam of low coherence optical radiation traveling a measurement optical path, leading the measurement beam towards the optical element and the reflected or diffused measurement beam towards an optical interferometric sensor arrangement, generating a reference beam of low coherence optical radiation traveling a reference optical path and leading the reference beam towards the interferometric optical sensor arrangement, superimposing the measurement and reference beams on a common region of incidence, detecting a position of a pattern of interference fringes between the measurement and reference beams, and determining a difference in optical length between the measurement and reference optical paths as a function of the position of the interference pattern along an illumination axis, or of the

Abstract: A spherical multi-axis optical fiber sensing device is formed by a three-axis optical interference sensor composed of a multi-level opto-mechanical integrated unit kit. The opto-mechanical integrated unit kit is composed of three fiber rings, which are respectively a large fiber ring, a medium fiber ring and a small fiber ring. The multi-level opto-mechanical integrated unit kit is combined with the use of the mechanism component technology that can be freely rotated and positioned to achieve the functional purpose of establishing a three-axis orthogonal optical fiber sensing unit in a single sphere volume.

Abstract: The invention refers to a frequency shifter for heterodyne interferometry measurements, comprising a chip, an input waveguide configured to guide a light beam, at least four phase modulators, each being arranged to receive the light beam from the input waveguide and configured to modulate a phase of the light beam, an output combiner being arranged to let the light beams modulated by each phase modulator interfere, a first output waveguide coupled to the output combiner and configured to receive the modulated light beams constructively interfering at the output combiner, a second output waveguide coupled to the output combiner and configured to receive the modulated light beams destructively interfering at the output combiner, wherein the input waveguide, the phase modulators, the output combiner, the first output waveguide and the second output waveguide are arranged on the chip.

Abstract: A method of optical measurement for determining a spatial position of at least one luminous object in a sample includes: projecting onto the sample a dynamically optimized sequence of compact luminous distributions of different topological families; wherein the dynamically optimized sequence is determined based on data selected from the group consisting of a positioning hypothesis and a first set of measures; for each compact luminous distribution in the optimized sequence, generating an image of the at least one luminous object as illuminated thereby; and algorithmically analyzing the generated images to obtain spatial position information of the at least one luminous object.

Abstract: A broadband interferometry for a measurement range extension beyond a coherence length of a light source is achieved through a local oscillation of the reference beam is replicated by a cavity multiplication or cascading optical delayed lines with a fiber optic cavity, and quantifiable optical properties including a wavelength group delay, a chromatic dispersion, a polarization mode dispersion and a model dispersion are inserted into the local oscillation of the reference beam to incrementally quantify the replicated copies of the local oscillation as the number of the delayed copies of the local oscillation increase for extension of a measurement rage to the target.

Abstract: An optical measurement system measuring optical parameters of an object is provided. The object includes at least two light-transmitting layers. The optical measurement system includes a light source module, an image capture module, and a controller. The light source module emits at least two measurement light beams toward the object. The measurement light beams are respectively incident on the object at different angles. The image capture module receives light spots formed on a sensing surface of the image capture module by at least two first light beams after the measurement light beams are reflected by the object and at least two second light beams after the measurement light beams are refracted and reflected between the object. The controller is electrically connected to the image capture module to obtain positions of the light spots. The controller calculates the optical parameters of the object according to the positions of the light spots.

Abstract: The invention refers to an optical device for heterodyne interferometry, comprising a chip, a beam splitter, a first waveguide arranged on the chip, light propagating in the first waveguide being guided to the beam splitter, a second waveguide arranged on the chip, light propagating in the second waveguide being guided to and/or from the beam splitter, wherein the beam splitter, the first waveguide, and the second waveguide form part of a Michelson interferometer, wherein the first waveguide and the second waveguide at least partially form two arms of the Michelson interferometer, and wherein two further arms of the Michelson interferometer are at least partially arranged outside the chip.

Abstract: This application discloses a measurement apparatus that does not use a femtosecond laser light source and a delay stage. The measurement apparatus mixes a first laser light from a first CW laser light source and a second laser light from a second CW laser light source to generate an interference light having a beat in a range from GHz to THz and demultiplexes the interference light into a pump light and a probe light. A generating photoconductive antenna is irradiated with the pump light, and a detecting photoconductive antenna is irradiated with the probe light. A current value of an electromagnetic wave propagating through a waveguide connecting the generating photoconductive antenna and the detecting photoconductive antenna is measured using a current system connected to the detecting photoconductive antenna.

Abstract: A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, a demodulation circuit that demodulates the sample signal from the light reception signal based on a reference signal, and an oscillation circuit that outputs the reference signal to the demodulation circuit, and the vibrator is a signal source of the oscillation circuit.

Abstract: Disclosed herein an apparatus and method for estimating a phase retarder and method of manufacturing the phase retarder using the same. The apparatus includes: a polarization element configured to output an incident light as a linear polarization and to make the linear polarization incident onto a phase retarder to be tested; a polarization image acquisition module equipped with a plurality of polarized pixels receiving an emitting light that is output from the phase retarder, on which the linear polarization is incident, and configured to obtain a polarization image based on the emitting light that is modulated in the polarized pixels; and a processor configured to evaluate quality of the phase retarder based on uniformity of a brightness value between polarized pixels of the polarization image. The polarized pixels modulate the emitting light based on a plurality of transmission angles and detects the modulated emitting light.

Abstract: A method for scanning a scene is disclosed. According to the method, light is transmitted by a transmitter through a transmitter surface grating array, as a first elliptical pattern in a first lateral direction. Light is received by a receiver through a receiver surface grating array, from an area of a second elliptical pattern. The received light is reflected from the first elliptical pattern. The first elliptical pattern is orthogonal to the second elliptical pattern. The first elliptical pattern overlaps with the second elliptical pattern.

Abstract: A composite measurement system for measuring nanometer displacement is provided. The system includes: a light source, a polarization beam splitting prism, a first phase change module, a second phase change module, a first right-angle prism, a second right-angle prism, a non-polarization beam splitting prism, a scalar interference light collection module, a vector interference light collection module and a displacement calculation module. In the present disclosure, a photodetector is configured to collect an intensity of scalar interference light of the object to be measured being moved, to obtain a periodic light intensity change curve; a CCD camera is configured to collect images of interference vortex light of the object being moved; and the displacement calculation unit is configured to calculate a displacement of the object according to integer periods of the light intensity change curve and angles of image changes of the interference vortex light.

Abstract: Embodiments disclosed herein include a diagnostic substrate. In an embodiment, the diagnostic substrate comprises a substrate, a circuit board on the substrate, and a spectrometer coupled to the circuit board. In an embodiment, the diagnostic substrate further comprises a processor on the circuit board and communicatively coupled to the spectrometer.

Abstract: The present disclosure provides an OCT imaging system to reduce or eliminate frequency-domain aliasing artifacts. The frequency is shifted using a carrier frequency to define a sampling range substantially centered on the carrier frequency. An image of the sample is generated from a displayed imaging range that consists of a subset of the frequencies within the sampling range. Furthermore, the system may be configured to determine the carrier frequency such that a Nyquist frequency corresponding to the shifted frequency is extended beyond either an upper or a lower bound of an OCT quality envelope corresponding to the first portion of light. Additionally, the carrier frequency may be determined such that a lower bound of the OCT quality envelope is greater or less than a zero-frequency DC limit.

Abstract: Systems, methods and device provided for combining or splitting laser beams, including a plurality of optical fibers for providing laser beams, an image relay lens for each of the plurality of optical fibers, positioning a prism beam combiner or splitter after the image relay lenses for combining or splitting the laser beams. According to another aspect, the a prism beam combiner or splitter may include a flattened tip to transmit a portion of an input laser beam, a position sensitive detector to receive the transmitted portion of the input laser beam to track a beam axis motion and provide feedback alignment error signals based on the beam axis motion, and a driver to receive the feedback alignment error signals and to drive a motor or piezo actuated beam steering minor based on the feedback alignment error signals, wherein a laser bond inspection method implements the described systems and methods.

Abstract: The invention discloses a four-quadrant interferometry system based on an integrated array wave plate. PBS splits an output laser light into two paths, the reflected light and the transmitted light are respectively transformed into reference light and measuring light, the reference light and the measuring light are converged in PBS, the converging light enters a signal receiving unit and is split into four beams, and the four beams irradiate on a four-quadrant interference signal detector with an integrated array wave plate. The invention solves the problems that the existing signal detection system occupies a large space, is not conducive to array integration, and cannot be used in scenes with high space and size requirements.

Abstract: A time-domain or frequency domain system includes, a sample light path between a source interface and a detector interface, a reference light path between the source interface and the detector interface, and a photonic integrated circuit, wherein the reference light path is at least partially separate from the sample light path, wherein the sample light path includes a forward sample light path between the source interface and a sample interface, and a backward sample light path between the sample interface and the detector interface, wherein the forward sample light path and the backward sample light path are at least partially provided by the photonic integrated circuit, and wherein the photonic integrated circuit includes an integrated sample-side polarization beam splitter arranged in the forward sample light path and the backward sample light path.

Abstract: A device for measuring a substrate for semiconductor lithography with a reference interferometer for ascertaining the change in the ambient conditions, wherein the reference interferometer comprises a means for changing the optical path length of a measurement section of the reference interferometer, and a method for correcting cyclic error components in the reference interferometer using same.

Abstract: A system for measuring the topography of a surface including a carriage assembly and a base assembly. The carriage assembly comprising a plurality of displacement-measuring probes coupled to a carriage support structure. The base assembly positioned adjacent to the carriage assembly and comprising at least one reference object with an opening sized to receive a test object. At least one of the carriage assembly or the base assembly is configured to translate with respect to the other in at least two directions to enable at least one of the displacement-measuring probes to measure a displacement to a reference surface of the reference object and at least another one of the displacement-measuring probes to measure a displacement to a target surface of the target object whose topography is measured.